This book might be considered a delayed response to Leo Kadanoff's essay of 6 years ago entitled, 1 "Fractals: Where's the physics?" Fractals and Disordered Systems is a useful and well-integrated selection of ten chapters describing theoretical and experimental progress over the past 5-10 years in fractals and the physics of disordered systems. As the editors (who are also the authors of Chapters 2 and 3 on percolation) point out in the Preface, the fractals field is developing at a very rapid pace, and this book is intended to fill the gap between advanced textbooks and the current journal literature. This pace of progress is possible because the theoretical needs cited by Kadanoff are being addressed.